Commercial Building energy audits vs retro-commissioning

Commercial buildings account for two-thirds of greenhouse gas emissions in New York City. Governments are now joining hands with the conglomerates and other business houses to address the issue upfront by pledging to go carbon neutral by 2050. This is taken care of by implementing the ambitious litigation of Local Law 97 which mandates for buildings over 25,000 square feet to meet new energy efficiency & greenhouse gas emissions limits by 2024. 

Energy auditing is one of the first steps towards efficient energy management of a building. The process comprises identifying, surveying and analyzing the energy usage of the building to facilitate optimization while reducing energy consumption, thereby increasing the savings of cost as well as energy. Energy auditing regards itself primarily with health and safety along with reducing energy consumption without hampering the operations. 

Energy audits ensure consistency, accuracy and quality as per ANSI/ASHREA/ACCA Standard 211-2018. It is dignified as the best practice for energy survey & analyses for purchases and providers of energy audits services.Purpose of Energy Audits reflects when the overall performance of the building is enhanced by saving energy and operational costs and by identifying and rectifying all problems related to building system operation, control & maintenance, increasing tenant/occupant satisfaction by looking into their complaints, reducing associated liability and improving indoor environmental comfort and quality, a rising concern in the pandemic phase. Moreover, also analyzing the Operations & Maintenance (O&M), personnel training needs along with providing the training, facilitating risk management and risk elimination, extending, equipment life-cycle, addressing the code issues. Essentially, increasing the asset value of the property.

Whereas, retro-commissioning is an organized process of documentation that identifies low-cost operational & maintenance improvements in the existing buildings. It includes a proper analysis of operating protocols, calibration and sequencing, cleaning and repairs, and training and documentation issues. The focus lies on mechanical equipment, lighting, and related controls to optimize performance as opposed to major equipment replacement.
It typically begins with studying past utility bills & conducts interviews with the facility personnel, followed by execution and analysis of diagnostic monitoring and functional tests of building systems. These are finally retested and re-monitored to fine-tune improvements, all of which results in improved indoor air quality, comfort, controls, & energy and resource efficiency. Before filing the report, as required by Local Law 87, owners must ensure for the retro-commissioning to have been completed by a retro-commissioning agent for the required base systems.
The Energy Conservation Measures (ECM) detected during retro-commissioning will typically demand re-programming controls, repairing dusty dampers, replacing faulty actuators, valves, variable speed drives and sensors. Building retro-commissioning will also thoroughly assess the building operators, and how its controls are being used because poor operational procedures imply energy wastage. The ECMS identified are mostly low cost/no cost measures. The purpose of retro-commissioning is to essentially optimize the existing system performance through fine tuning and upgrades rather than relying on major equipment replacement (which energy audits might). Besides, the analysis will help the owners make informed decisions when considering improvements to the facility and well, avoid costly pitfalls in the future.

As already mentioned, Local Law 97 is one of the most determined plans for reducing emissions. It was included in the Climate Mobilization Act which was passed by the City Council in April 2019 as part of the Mayor’s New York City Green New Deal.

Under this pioneering law, most buildings over 25,000 square feet will be required to meet new energy efficiency and greenhouse gas emissions limits by 2024, with stricter limits coming into effect in 2030. The goal is to reduce the emissions produced by the city’s largest buildings 40 percent by 2030 and 80 percent by 2050. The law has also successfully established the Local Law 97 Advisory Board and Climate Working Groups to advise the city on how best to meet these unavoidable and now urgent sustainability goals.